气固两相流输送特性的试验研究

Experimental Research on Transportation Properties of Gas-Solid Two Phases Flows

为了研究柱塞式气力输送气固两相流的输送特性,对实际的工业气力输送系统进行1∶1实验台改造,首先进行了粉煤灰在输送管内的流动模式试验;然后进行粉煤灰输送压力、输送质量流量特性试验;最后考察了主进气流量、补气流量、助吹气流量对粉煤灰输送量、固气比的影响。研究表明:柱塞式气力输送流动模式以密相栓柱流为主,其灰栓长度为0.8-2.3m,移动速度约为2.8-11.3m/s;输送压力与输送流量成双曲线特性,且随着气量的增加输送量增大;主进气流量起主导作用并与输送粉煤灰质量流量成单调上升抛物线关系,与固气比成上凸抛物线关系即先增大后减小。研究结果对柱塞式气力输送系统的工程设计、运行和理论研究提供依据并具有指导作用。

For the purpose of researching the slug pneumatic conveying characteristics of gas-solid two phase flow, a 1 ： 1 improvement of test bench for the pneumatic conveying system in actual industry was conducted. A series of tests were carried out： firstly, the test for the flow modes of fly ash in conveying pipes ; then the test for the conveying pressure and the mass flow ratio of fly ash ; finally, the research of the influence from main conveying gas, fluidizing gas and adjustment gas to the mass flow ratio and solid-gas ratio. The test results indicated that the flow mode of the slug pneumatic conveying is mainly based on the slug-flow of dense phase, of which, the slug-flow is 0.8 - 2.3 meters long under the conveying speed of 2.8 -11.3m/s; with the hyperbolic characteristic of conveying pressure and mass flow, the mass flow increases along with the rise of the amount of gas; the main conveying gas plays leading role in the process, which has monotonously rising parabolic relation with the mass flow ratio of the fly ash, as well as convex parabolic relation with solid-gas ratio （first increased and then decreased）. The research results will provide basis for and be directive for the engineer design, operation and the theoretical study of the slug pneumatic conveying systems.